Electric vaporizer



United States Patent ELECTRIC VAPORIZER Joy B. Schmitt and William H. Corbett, Somerset, Pa., assignors to The De Vilbiss Company, Toledo, Ohio, a corporation of Ohio Application November 5, 1956, Serial No. 620,506

Claims. (Cl. 21940) This invention relates to Vaporizers utilizing an electrical heating element for generating steam and particularly to such a device adapted to provide steam vapor either alone or in combination with a vaporized medicament for the treatment of colds, coughs, bronchitis and other disorders of the respiratory system. Such devices are well known and have long been used in considerable number with beneficial results.

A source of considerable difficulty in the operation of these devices is the accumulation of precipitants from the water upon the electrodes and elsewhere which interferes with or disrupts proper functioning.

Also the electrolytic action in combination with inorganic substances in the water frequently corrodes the electrodes in a very short time to the point where they operate very inefiectually. This occurs particularly in areas of the country having water of unusual hardness.

Because of the electrical circuit and the presence of water the design of these Vaporizers must be carefully selected to guard against the hazard of electrical shock.

An important object of this invention is to provide an electric vaporizer which is comparatively free of difficulty caused by an accumulation of precipitants.

More specifically it is an object of this invention to provide a vaporizer in which the electrodes are so mounted they need no spacing elements below the water line.

A further object is to provide a vaporizer with electrodes which will stand up for long periods of use under the most corrosive conditions.

An additional object is a vaporizer which generates and discharges steam in a steadier flow.

Another object of the invention is the provision of an electrical vaporizer that has an improved factor of safety.

The features of the invention which are mostly responsible for the attainment of the above objects include: the rigid form of the electrodes and their mounting against tapered surfaces in a manner that permanently aligns them in spaced relation without the need of conventional spacing means between the electrodes below the water level; the unusual nickle-free stainless steel composition of the electrodes which stands up amazingly under severe cor rosive conditions; a partition within the head of the vaporizer between the steam outlet and the electrodes which prevents direct access to the electrodes through the steam outlet; and the special positioning of the water inlet port in the base of the electrode casing.

A better understanding of the features of the invention as well as the objects and advantages may be obtained by reading the following description and referring to the accompanying drawings in which;

Figure 1 is a vertical section of a vaporizer embodying this invention;

Figure 2 is a vertical section taken on line 2-2 of Figure 1 showing the electrodes forming the heating element and the casing enclosing the electrodes;

Figure 3 is a horizontal section taken on the line 3-3 of Figure 1; and

Figure 4 is an enlarged broken sectional view com 2,818,486 Patented Dec. 31,1957

parable to that of Figure 3 showing the mounting of the electrodes.

The vaporizer illustrated in the drawings has a receptacle 1 for the water from which the steam is generated. Positioned upon and extending into the receptacle is a generally cylindrical casing 2 forming a housing 3 within the receptacle for the heating electrodes 4 and 5. The casing has at its upper end a radially projecting border 6 with a downwardly turned flange 7 which fits around the neck of the receptacle.

Upon the casing secured by bolts 8 is a cover 9 having an exterior well 10 for holding any medicament to be vaporized and combined with the steam issuing from discharge port 11 and passing over the well. Within the cover in communication with discharge port 11 is steam expansion chamber 12. V

The electrodes 4 and 5 of duplicate shape are suspended in housing 3 from the rearward wall 13 of the steam chamber 12. They are held in place by square nuts 14 on the threaded ends of terminals 15 and 16 which extend through the wall 13 from the enclosure 17. This enclosure is open on the side away from the wall 13 for the reception of an electrical plug into engagement with the terminals.

The lower end of the electrode housing 3 is eccentrically ported at 18 for the restricted entry of water from the receptacle.

The electrodes 4 and 5 are formed of stainless steel sheet stock. Their main portions are in spaced parallel relation and shallow U shape in cross section with the open side of the U configuration facing away from the other electrode. Horizontally turned feet 23 on the electrodes are also directed outwardly.

The electrodes are held rigidly in spaced relation by their special mounting arrangement.

The upper end of each electrode is compressed U-shape in horizontal section, its sides being bent toward each other into parallel relationship in planes normal to that of the flat main portion of the electrode. Through this shaping the electrodes present flat areas for flush contact upon wall 13 and to which the horizontally positioned terminals 15 and 16 may be readily attached by nuts 14. The latter are placed between the sides which are bent in U shape. A fin 29 from wall 13 provides an insulating partition between the upper ends of the electrodes.

Of particular importance is the broad tapered base 30 of the fin, which is utilized in establishing and anchoring the electrodes in their parallel spaced arrangement. The position of the holes through which the terminals 15 and 16 project for threaded attachment of the nuts 14 and the other elements involved are so correlated that the clamping of the electrodes through the engagement of the nuts with the terminals brings the adjacent vertical edges of the electrodes against the opposite lower edges of the tapered base 30. The contact forces the electrodes to conform to the straight longitudinal form of the taper and provides a positive, parallel, spaced positioning of the electrodes in spite of slight variations arising from manufacturing tolerances.

This mounting is most etfective for proper assembly and also assures a permanent retention of the electrodes in their proper operating placement. The design of the electrodes with the side flanges makes them individually rigid throughout their otherwise unsupported lengths.

It has always been considered necessary to have a frame or other type of spacer below the water level of electric Vaporizers to hold the electrodes apart. The use of such separators has continued over many years in spite of the many failures of the Vaporizers due to the deposit of precipitants upon the separator devices and the consequential short circuit between the electrodes. For the first time this cause of serious and repeated 3 troubles has been eradicated by a design doing away with the need of spacing devices.

Another surprising innovation of this invention is the composition of the electrodes. It has long been recognized that under the severe conditions of their operation the electrodes of stamped design must be highly resistant to corrosion. Consequently it has been accepted as standard practice to utilize special sheet metal of fine quality stainless steel in their fabrication. lnvariably, the stainless steel has been a high nickel-containing alloy considered by those in the industry and by the steel suppliers as the most reliable. The nickel content in such steels range from about eight to fourteen percent.

Against established practice and the previously unquestioned opinion of experts in the art, applicants ran extended tests on a less expensive, lower grade of stainless steel not incorporating a nickel constituent and found that electrodes of such composition were many times superior to those of the recommended composition.

This was such an unnatural finding that the steel mill to which it was reported would not accept its authenticity until they had made confirming tests. They were at a loss to provide a precedent or even an explanation for the confounding results.

In operating the vaporizer of this invention the glass jar constituting the water receptacle 1 is filled about three quarters full with ordinary tap water which usually carries enough minerals to support satisfactory operation of the vaporizer. If the mineral content is exceptionally high the electrolytic action between the electrodes causes excessive boiling. Such water may be tempered by adding rain water or commercial distilled water. At the other extreme, tap water may be too soft and a pinch of salt must be added to form an electrolyte to speed up the boiling action.

With the vaporizer replaced over the receptacle any desired medicament is placed in the well 10 but preferably not more than enough to half fill it. Tincture of henzoin is frequently used as its vapors are generally beneficial. The plug of an attachment cord is then slipped over terminals 15 and 16.

The lateral entry of the plug into the terminal enclosure 17 is considerably safer than the usual open topped terminal housing, as water or medicine spilled from above the vaporizer or condensed steam settling upon the vaporizer is shielded from the terminals. As such liquid could build a short between the terminals or to the hand of a person moving the vaporizer there is real reason to guard against such an accident. An annular gutter 27 around the top of the casing 2 drains any water collecting there through passage 28 into the receptacle 1.

With the current reaching electrodes 4 and 5 electrolytic action through Water between the electrodes results and this water is brought to a boiling temperature within a short interval. The steam vapor formed rises from housing 3 into the steam chamber 12 bounded on the lower half by the enlarged section of the cylindrical casing 2 and on the upper half by the interior cavity of cover 9. The steam under its own pressure is projected through discharge port 11 as a strong flaring stream.

Behind port 11 within steam chamber 12 is a Web 20. This is positioned to intervene between port 11 and the electrodes. There are two purposes served by this web. In the first place it adds to the safety of the vaporizer by hindering a Wire or other metal article employed to clean the port 11 from reaching the electrodes and causing a short circuit through the metal article to the hand of the user. The partition further acts to intercept salt introduced through the discharge port and direct it down into the receptacle as an electrolyte additive in the water; the partition directs the salt away from contact with the 4 electrodes. If deposited upon the electrodes or between them at their upper mounting ends, salt increases corrosion or the chance of short circuiting.

Another design feature forming a part of this invention is the location of port 18 through which water is admitted at the bottom of the electrode casing to replace that consumed in steam generation.

It has been previous practice to place this entry port at the center of the bottom of the casing. Applicants discovered that the spurt of cooler water through the centrally located port and up between the electrodes was responsible for periodic recession of the steaming action. By positioning the port laterally so that the increments of water were introduced to the outside of the electrodes the undulations in the steam production were moderated.

it may be noted that the medicament well 10 is air insulated on three sides and bottom but receives heat from the steam chamber through the wall below discharge port 11. Consequently vapor arises from the medicament more strongly in the vicinity of this wall and is thus more subject to the aspirating efl'ect of the steam jet and is more readily drawn up into confluence and travel with the steam. Accordingly, little of the medicinal vapor is lost through vagrant dissipation and that combined with the steam is elfectively carried to the person under treatment.

It is the opinion of many physicians that steam vapor alone is therapeutic and may be applied for several hours or overnight. The vaporizer of this invention is provided with a water capacity capable of sustaining steam discharge at a high rate for extended periods of treatment up to twelve or fourteen hours long.

The length of automatic operation is of course proportional to the amount of water placed in the receptacle. As the water is boiled away the water level recedes below the lower ends of the electrodes breaking the flow of current and terminating steam formation.

When it is desired to disassemble the vaporizer for periodic cleaning to remove mineral deposits from the electrodes and the interior of easing 3, the cover 9 is easily separated from the casing by unscrewing bolts 8. In order to prevent exposing the electrodes while they still carry an electrical charge, one of the bolts 8 is positioned beneath the attachment plug when the latter is in contact with the terminals 15 and 16. Accordingly, to remove the bolt it is first necessary to withdraw the attachment plug breaking the electrical connection.

Although a particular embodiment of this invention has been shown and described, it will be understood that various modifications may be made without departing from the scope of the invention.

What we claim is:

1. In an electric steam vaporizer of the type described, a receptacle for the water to be heated, and a pair of vertically elongated electrodes suspended in the receptacle and adapted to heat the water and generate steam by the passage of an electrical current between them, said electrodes being rigidly constructed of sheet steel, and means mounting and aligning the electrodes at their upper ends and holding them firmly in predetermined spaced parallel relation with their lower ends free of any supporting or spacing elements, whereby there are no elements between the portions of the electrodes submerged in the water, on which precipitants may accumulate.

2. An electric steam vaporizer according to claim 1 in which the mounting-means includes a vertically extending element with sides diverging to its base and retaining means clamping the electrodes with the element between them and with the adjacent vertical edges of the electrodes pressed against the diverging sides.

3. An electric steam vaporizer according to claim 1 in I which the mounting means includes a generally flat vertical wall against which the electrodes are held and a ridge with inclined side surfaces between the electrodes and along which the adjacent edges of the electrodes abut and are vertically guided.

4. An electric steam vaporizer comprising a receptacle for the water to be heated and a pair of vertically elongated electrodes suspended in spaced parallel arrangement within the receptacle to serve in heating the water, said electrodes being shaped of stainless steel sheets of a nickelfree composition.

5. An electric steam vaporizer comprising a receptacle for the water to be heated, a head member mounted on the receptacle and having a steam chamber, said chamber partially defined by a forward vertical wall and a rearward vertical wall in opposed relation, a discharge port through the forward wall of the chamber, a pair of electrodes sus- References Cited in the file of this patent UNITED STATES PATENTS Fisher et al July 17, 1956 Duberstein et al Sept. 18, 1956 

